Currently, many people suffer from insomnia. The insomnia refers to a symptom including “sleep onset insomnia” such as difficulty in falling asleep in the night, “middle-of-the-night insomnia” such as difficulty in maintaining sleep, “sleep offset insomnia” such as waking up early in the morning. If such a symptom continues, it is difficult to sleep well. Therefore, this causes sleepiness during daytime, distraction of attention, fatigue, or various physical disorders.
In the related art, there is known a system for managing sleep of a user from the viewpoint of improvement of sleep quality of the user (for example, see Patent Document 1). In the system described in Patent Document 1, one or more objective parameters regarding the sleep quality of the user who is in bed are monitored, and a feedback of objective test data measured for a cognitive ability or a psychomotor ability during a wake-up time of the user is presented to the user via a portable device such as a mobile phone.
Patent Document 1 describes a method of measuring a response time as an example of the cognitive ability test or psychomotor ability test (method of measuring accumulated sleepiness, feeling disorders, and degradation of the psychomotor ability caused by insomnia when a user has sleep limited to four to five hours per night, for one week). In the system described in Patent Document 1, in order to improve the future sleep quality on the basis of a result of the cognitive ability test or the like, information for affecting a user's behavior (such as a warning, guidance, advice, or a message for encouraging the user) is presented to the user.
In addition to Patent Document 1, a method of performing the sleepiness test on the basis of the response time is known (for example, see Patent Documents 2 and 3). Patent Document 2 describes a technique of detecting a response from a user to a generated vibration and determining a user's wakening level on the basis of an actual time length during which there is no response from the user. Patent Document 3 describes a technique of designating and notifying a user to select any one of operation switches randomly set using a sound output of a loudspeaker and determining a sleepiness degree of the user from response time information taken until the designated operation switch is operated.
In the system described in Patent Document 1, since information such as a warning, a guide, advice, or a message for encouraging the user is presented on the basis of a result of the test or the like through measurement of the response time of the user, the sleep quality is improved when the user takes actions in accordance with the content.
Note that insomnia is not cured immediately even when the user takes actions once in accordance with the presented information depending on the result of a single test. For this reason, it is necessary to continuously perform the test and continuously take actions for improving insomnia.
Patent Document 1 describes a technique of periodically executing the test while a user is awake on the basis of a fact that the cognitive ability or the psychomotor ability changes throughout the entire day. In addition, Patent Document 1 also describes a technique of randomly or sporadically performing the test while the user is awake. Specifically, the cognitive ability test or the psychomotor ability test is performed several times a day for several days over a wide range of time. The user is prompted by a portable device to execute the test at a regular time everyday for several days.
Patent Document 1: JP-A-2011-36649
Patent Document 2: JP-A-2012-40134
Patent Document 3: JP-A-2015-115045